Abstract:

Objectives: To verify the accuracy of measuring the plasma renin and aldosterone by chemiluminescence immunoassay (CLIA) and assess its diagnostic efficacy in primary aldosteronism (PA). Methods: The plasma renin and aldosterone level were detected in out-and in-patients using CLIA, enzyme-linked immunosorbent assay(ELISA) and radioimmunoassay, and the intravenous saline infusion test was conducted as confirmatory test. The consistence among three tests was assessed with Pearson correlation analysis and Bland-Altman analysis. The aldosterone and renin level detected by CLIA were used to calculate aldosterone to renin ratio (ARR). The receiver operator characteristic curve （ROC curve） was performed to determine the optimized ARR cut-off value and the area under ROC curve (AUC) for diagnosing PA. Results: The aldosterone and renin concentration detected by CLIA were significantly correlated with the results tested by ELISA(rennin and aldosterone concentration) and radioimmunoassay (renin activity and aldosterone concentration) respectively（r≥0.67, P<0.01; r≥0.79, P<0.01）. Compared with that by CLIA using blood collection tube with the enzyme inhibitor, rennin concentration by CLIA using blood collection tube without enzyme inhibitor had a better correlation with renin activity by radioimmunoassay (correlation coefficient: 0.80 vs. 0.67, P<0.01). In 45 hypertension patients, the AUC of ARR acquired by CLIA for diagnosing PA was 0.91 and the optimized ARR cut-off value was 18.26 [(pg/mL)/(pg/mL)], and both sensitivity and specificity were 86.7%. Conclusions: CLIA could be used for clinical PA screening as a reliable detective method since it has high accuracy of measuring plasma renin and aldosterone.

Key words: Primary aldosteronism, Renin, Aldosterone, Chemiluminescence immunoassay, Radioimmunoassay